Monohybrid Cross Problem Set

Problem 9: Incomplete dominance

In Mendel's experiments, if the gene for tall (T) plants
was incompletely dominant over the gene for short (t)
plants, what would be the result of crossing two Tt
plants?

Tutorial

A cross of two F1 hybrids, heterozygous for a single trait that
displays incomplete dominance is predicted to give a 1:2:1 ratio
among both the genotypes and phenotypes of the offspring. 1/4 will
have the dominant phenotype (tall, TT), 1/2 will have the intermediate phenotype
(Tt) resembling the parents of this cross, and 1/4 will have the recessive
phenotype (short, tt.) When incomplete dominance
occurs, it is not necessary to do a test cross to identify the
heterozygotes.